Title: Constructive & Destructive Forces on Landforms
1Constructive Destructive Forces on Landforms
2Two Types of Forces
- Destructive Forces processes that destroy
landforms. - 2 types Slow (weathering) and Fast (Erosion)
- Ex. landslides, volcanic eruptions, earthquakes,
floods - Constructive forces forces that build up an
existing landform or create a new one. - Caused by water, gravity, wind and glaciers.
- Ex deposition, landslides, volcanic eruptions,
floods
3Weathering
Weathering Pictures
- Weathering a slow, destructive force that breaks
rocks into smaller pieces called sediments. Can
by physical (mechanical) or chemical. - Keywords
- wear down, break
- apart
4Mechanical weathering the breaking of rock into
smaller pieces by forces due to gravity, ice,
plant roots, or other physical forces.
5Chemical Weathering the changing of materials in
a rock by chemical processes.
6Erosion
Grand Canyon Video
- Erosion the destructive movement of materials
away from one place by wind, water, ice and
gravity.
Wave Erosion- caused by water
Wind Erosion (Dust Storm)
7Landslides
- Landslides occur when gravity quickly pulls rock
and dirt downhill.
8Floods
- Floods a great flow of water over an area that
is usually dry land.
9Volcanic Eruptions
- Volcano an opening in the Earths crust through
which steam, lava and ashes erupt. - Cause both destructive and constructive changes
to landforms.
10Mount St. Helens
Mount St. Helens Video
Saint Helens Before
Saint Helens After
11Volcanoes can be constructive, but also
destructive
12Earthquakes
- Earthquakes the shaking of Earths surface
caused by the release of energy along a fault.
San Andreas Fault, California
13Volcanoes Earthquakes
Tectonic Plates, Volcanoes Earthquakes
14Erosion Deposition
- Deposition the placing of materials in a new
place (constructive force). - Ex. Sandbars
15Water Erosion Deposition
- River Delta- Deposits of sediment at the mouth of
the Mississippi River creating new land called a
delta.
16Wind Erosion Deposition
- Sand Dunes- sand is moved by wind
Desert Sand Dunes
Ocean Sand Dunes